I will concur, they do not take reservations. And that is annoying, especially with the crowds they draw.
But, if you want to have the best cheese curds, EVER, you will need to fight the crowds to get a table (or seat at the bar) here. They have some very interesting menu items, but they also have some really yummy salads if you are not in the mood for the other stuff. I have consistently gotten the portabella sandwich and the walleye, but I will be honest, it is the cheese curds that bring me back.